Guardline Protocol Analyzer

Guardline Protocol Analyzer for Saleae Logic software

This analyzer protocol works with Guardline Wireless Driveway Sensors

Other Information

The sensors use FSK modulation at 914.8MHz and 20Kbps.

Transmitter chip: Melexis TH72031

Receiver chip: Amiccom A7201B

Has not been tested with the 1/4 mile version of the sensors.

This project is based on the SampleAnalyzer example from Saleae

Instructions

1. Build project via Visual Studio files (Windows) or python build scripts (Linux/Mac)
2. Add output path in Logic software under Preferences/Developer in the Search this path for analyzer plugins box.
3. Restart Logic.

Protocol

The Guardline protocol seems to consist of a 24bit ID + 1 extra bit.

Each bit in the ID is represented by one symbol, or 3 bits in the data stream.

Symbols follow the pattern X10 where X is the data bit and the trailing 1 and 0 is for communication reliability (I assume).

So the symbols we are looking for are 010 and 110 to represent HIGH/LOW.

The ID will repeat 30+ times when the sensors transmit.

Usage

The Serial channel is the channel the data will be on

The Label channel is just used to display bit information for the data on the Serial channel

Period is the average time in microseconds for one bit in a symbol.

Gap Time is the time between each ID repetition.

Example